This application has subject matter in common with the inventor's U.S. patent application Ser. Nos. 12/318,473 (“LED night light with laser or hologram elements”); 12/318,470 (“LED projection night light”); 12/318,471 (“LED light has pinhole-imaging”); 12/292,153 (“LED night light has projection or image feature”); 12/232,505 (“LED night light with Projection features”); 12/149,963 (“Removable LED light device”); 12/073,889 (“LED track light device”); 12/073,095 (“LED light with changeable position with Preferable power source”); 12/007,076 (“LED light with changeable geometric system”); 12/003,691 (“LED light with changeable geometric dimension features”); 12/003,809 (“LED light with changeable features”); 11/806,711 (“Multiple LED light with adjustable angle features”); 11/527,631 (“Night light with interchangeable display unit”); 11/498,881 (“Poly Night light”); 11/255,981 (“Multiple light source Night Light”); 11/094,215 (“LED Night light with Liquid optics medium”); 11/092,741 (“Night light with fiber optics”); 10/883,747 (“Fiber Optic light kits for footwear”); 11/498,874 (“Area Illumination for LED night light”); 11/527,629 (“Time Piece with LED night light”); 11/527,628 (“Multiple Function Night light with Air Freshener”); 11/806,284 (“LED Night light with more than one optics mediums”); 11/806,285 (“LED Night Light with multiple function”); and 11/806,711 (“Multiple LEDs Light with adjustable angle function”).
Of the above, U.S. patent application Ser. Nos. 11/527,631; 11/498,881; 11/255,981; 11/094,215; 12/318,470; 12/318,471; and 12/318,473 all disclose an “AC power sealed-unit” and “DC powered battery-pack” that are interchangeable with each other to fit into a “uniform compartment” on the LED light housing. The current invention also involves an interchangeable sealed AC unit and a DC battery pack, for all kinds of applications that may include an LED, such as a toy, gift, game, lighting, camping light, car, miniature cars, sound device, video device, music device, or touch device. However, the current invention differs from the inventions of the seven applications that also disclose sealed units in the following respects:
(1) Light source:                The earlier filings are limited to an LED as light source. The current invention covers all low power consumption light elements, including electro-luminescent elements as well as LEDs, as the light source.        
(2) Light Source within Current Light Device for Common Use:                The current light source may be common to both the sealed-unit and battery-pack so that there is no need for the sealed-unit and battery-pack to each have its own light source. The earlier applications of the inventor each disclose a sealed-unit and battery-pack having its own LED within its own housing.        
(3) Light Source Definition:                The light sources of the current invention can all be turned on by DC electric signals supplied by only three relatively low voltage fresh batteries (such as three Duracell™ alkaline AA batteries) to provide a light performance that last more than one hour.        
In addition, the sealed unit or battery pack of the current invention offers the further improvement that it has its own trigger means, which may include any of a push switch, slide switch, conductive switch, sensor, motion sensor, vibration switch, tilt switch, heat switch, moisture switch or any mechanic or electric switch available from the convention market and that can be selected to use for a DC powered battery light device.
The current invention has wide application for any DC powered battery items capable of providing a “compartment with uniform connect-means,” because is easy to design the “AC powered sealed-unit” and “DC power battery-pack” with the above discussed trigger means to fit each of the existing battery powered application listed above so that any such battery powered application can be converted to an AC powered lighting device by replacing the battery pack with an “AC powered sealed-unit” that can be plugged into wall outlet. This will let people buy one battery-powered application and yet make use of two different power sources for different location requirements. For example, one could buy a bathroom floating LED battery operated toy light that can be changed into an AC powered LED night light to plug into a wall outlet and become a very cute and eye-catching device. If people think such a device is too toy like, fine—one could instead change the kids' battery powered LED flash light to an AC powered flashing light to plug into a wall for night time illumination, which is more similar to a conventional market night light.
The current invention can also, conversely, change a safety AC powered light device into a DC powered battery light device by simply swapping the AC powered sealed-unit for a DC powered battery-pack. This will enable all conventional nice looking AC power night lights to become battery powered night lights. Furthermore, it will be noted that the change to DC powered light devices enabled by the invention can be applied to all conventional low power consumption AC light devices because all such light sources use direct current to drive them and so one can use the interchangeable features of the invention for all light devices of all kinds of categories as long as they are low power consumption light devices as described above.
The invention thus provides an interchangeable power source for any lower power consumption light device, enabling the light device to utilize both an AC power source and a battery-operated power source.